Magento2: Setup script doesn't work

Please, how can i resolve this problem? my setup script doesn't work when i enable my module using this command:

php bin/magento module:enable Demo_Demo

<?php


namespace Demo\Demo\Setup;

use Magento\Framework\Setup\InstallSchemaInterface;
use Magento\Framework\Setup\SchemaSetupInterface;
use Magento\Framework\Setup\ModuleContextInterface;

class InstallSchema implements InstallSchemaInterface
{
    public function install(SchemaSetupInterface $setup)
    {
        $setup->startSetup();

        $data = [];
        $statuses = [
            'demo_payed' => __('payed'),
            'demo_error' => __('error'),
            'demo_processing'  => __('processing'),
        ];
        foreach ($statuses as $code => $info) {
            $data[] = ['status' => $code, 'label' => $info];
        }

        $setup->getConnection()
            ->insertArray($setup->getTable('sales_order_status'), ['status', 'label'], $data);

        $setup->endSetup();
    }

}